Untersuchungen zur Kn�pfung der Peptidbindung mit ?-trifluormethylsubstituierten ?-Aminos�uren
作者:Wolfgang Hollweck、Klaus Burger
DOI:10.1002/prac.19953370183
日期:——
The reaction of ol-trifluoromethyl substituted N-(t)butoxycarbonyl amino acids (Boc-TFM-Xaa-OH) 1 with dicyclohexylcarbodiimide results in formation of 2-(t)butoxy-4-trifluoramethyl-5(4H)-oxazolones 2 within minutes. Compounds 2 react with amino acid esters to give Boc protected dipeptide esters 4. However, at room temperature compounds 2 decompose to give Leuchs anhydrides 3, via retro-ene reaction. Therefore, alpha-trifluoromethyl substituted N-(t)butoxycarbonyl amino acids (Boc-TFM-Xaa-OH) are of limited value for peptide synthesis.